Givhan notes that, as far as shorts go, these weren't bad—not too baggy nor too tight. But in her opinion, shorts have no place anywhere but in the private realm, and Air Force One is not private. I don't know if I completely agree with that, but I wholeheartedly agree that shorts are an emblem of the casual-and-comfortable-at-all-costs mindset that defines most Americans' everyday style. She encapsulates it perfectly in one short paragraph:

The reality is that a good portion of the culture has become loudly vocal about how clothes don't matter and how it's snobbish or shallow to suggest that they do. But clothes are part of our broader aesthetic obligation to each other. That commitment pushes homeowners to mow their lawns and not be a blight to the neighborhood. It makes them think twice before painting their houses in psychedelic stripes. The desire to be aesthetically respectful means guests give consideration to what they wear to a friend's wedding or mourners take care in how they dress for a loved one's funeral.

At HuffPo, Gioia Diliberto says that maybe the First Lady just wanted to be comfortable. But she also notes that in Paris young women are wearing cutoff jeans shorts (albeit dressing them up with jackets and heels).

Here in Chicago, it's already moot: it's been too chilly the past several days to wear anything but layers.